1. Field of the Invention
The present invention relates to a gas turbine apparatus having a heat exchanger for exchanging heat between compressed air ejected from a compressor and exhaust gas ejected from a turbine.
2. Description of the Related Art
In some gas turbine, a heat exchanger is installed in order to increase the thermal efficiency and heat is exchanged between exhaust gas ejected from the turbine and compressed air before introduced into a combustor after ejected from a compressor. In this case, in order to introduce and eject compressed air from the compressor of the gas turbine into and from the heat exchanger, pipes are generally used. Accordingly, the energy loss of compressed air due to heat dissipation and frictional resistance in the pipes is increased and the whole size of the gas turbine apparatus is made larger.
On the other hand, a gas turbine apparatus with the heat exchanger that is directly connected to the back of the gas turbine so as to omit the pipes and to realize compactness is known. However, in this gas turbine apparatus, the combustor of the gas turbine is installed on the heat exchanger side. Therefore, when the type of combustor is changed, another heat exchanger corresponding to the combustor of new type must be prepared and the design of the heat exchanger must be changed in accordance with the type of combustor, resulting in increasing in cost.
The present invention was made with the foregoing in view and is intended to provide a gas turbine apparatus having a heat exchanger that no pipe is required, and efficiency improvement and structural compactness are realized, and the common heat exchanger can be used even if the type of combustor is changed, and the cost can be reduced.
To accomplish the above-mentioned object, the gas turbine apparatus of the present invention has: a gas turbine having a compressor, a combustor, and a turbine rotor; and a heat exchanger attached to said gas turbine for exchanging heat between a compressed air ejected from said compressor and an exhaust gas ejected from said turbine rotor, said heat exchanger being connected to an exhaust gas outlet side of a back portion of said gas turbine, said heat exchanger having a core including a front, a back and a side, and a casing enclosing said core, said core including a plurality of heat transfer plates that partition an internal space of said core into a first path for flowing said compressed air and a second path for flowing said exhaust gas. An inlet for flowing said compressed air into said first path is formed on said side of a back portion of said core. An outlet of said compressed air passing through said first path is formed on said side of a front portion of said core. An introduction path is formed between said core and said casing so that said compressed air is introduced through said introduction path from a position in front of said core via an outside of said side of said core into said inlet. Said exhaust gas is introduced from said front of said core into said second path and ejected from said back of said core.
According to the gas turbine apparatus aforementioned, the heat exchanger is connected to the exhaust gas outlet side of the back portion of the gas turbine including the combustor, and between the core of the heat exchanger and the casing, the introduction path for introducing compressed air into the inlet of the core from a position in front of the core via the outside of the side of the core is formed, and on the side of the front portion of the core, the outlet of compressed air passing through the first path is formed, so that a pipe for introducing compressed air into or ejecting the same from the heat exchanger is not necessary. As a result, the energy loss of compressed air by such pipe is eliminated and the whole gas turbine apparatus can be made compact. Moreover, the inner peripheral surface of the casing faces on the introduction path for flowing low-temperature compressed air, so that it can be expected that the casing is suppressed from high temperature and also heat of the heat dissipation from the core is recovered by compressed air in the introduction path. Further, on the back portion of the gas turbine including the combustor, the heat exchanger that is separately structured from the gas turbine is attached. Accordingly, regardless of the type of combustor, by use of the common heat exchanger, feed of exhaust gas to the heat exchanger, feed of compressed air ejected from the compressor to the heat exchanger, ejection of compressed air from the heat exchanger to the combustor, and ejection of exhaust gas from the heat exchanger can be carried out, thus designing is made easy and the cost can be reduced.
Preferably, an ejection path for ejecting said compressed air from said outlet into said combustor of said gas turbine in front of said core is formed on a radially inner position with respect to said introduction path. An inlet path for flowing said exhaust gas into said second path of said core is formed on a radially inner position with respect to said ejection path. An exhaust port for ejecting outside said exhaust gas passing through said second path is formed on a back of said heat exchanger.
According to this constitution, in front of the heat exchanger, the introduction path toward the heat exchanger for flowing low-temperature compressed air, the ejection path toward the combustor for flowing slightly high-temperature compressed air, and the exhaust gas inlet path for flowing very-high temperature exhaust gas to the heat exchanger are arranged in a triple structure from the radially outer position to the radially inner position, and exhaust gas passing through the heat exchanger is ejected outside from the back of the heat exchanger, so that the triple structure symmetrical with respect to the rotational axis of the gas turbine can be easily formed, for example, by a sheet metal. Namely, introduction of compressed air from the compressor to the heat exchanger, flowing of exhaust gas from the turbine to the heat exchanger, ejection of compressed air from the heat exchanger to the combustion chamber, and ejection of exhaust gas from the heat exchanger can be realized by a simple and compact structure. Moreover, since the exhaust gas inlet path, ejection path, and introduction path are arranged so that low-temperature gas sequentially flows from the radially inner position to the radially outer position, temperature rising of the outer periphery of the triple structure can be suppressed effectively and it can be expected that by heat exchange through the path wall such as the sheet metal aforementioned, compressed air ejected from the heat exchanger is heated by exhaust gas.
Preferably, said casing has a circular cross section. Said combustor is annular. Said casing and said combustor are arranged concentrically with respect to a rotational axis of said gas turbine.
In such a constitution, the location relationship of the gas turbine including the combustor and the heat exchanger behind the gas turbine can be set easily and precisely.